Binding lightning:input checkbox value. Must bind to 'checked' not 'value'

gistfile1.txt

<aura:attribute name="testBoolean" type="Boolean" default="false" />

<lightning:input name="testBoolean" label="Test Boolean" type="checkbox" checked="{!v.testBoolean}" />

Hey, does this fire onChange event?

Yes but the 'c' is lowercase. ie. onchange.

From the docs : "You can define a client-side controller action for input events like onblur, onfocus, and onchange." https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/aura_compref_lightning_input.htm